The Beautiful Biomechanics of the Power Serve: Part 2

By Chris Lewit

In Part 1 on the serve (Click Here), I introduced the 8 stage model of the serve with 3 phases. In Part 2, we are going into much more technical detail about each stage.

To win pretty with the serve, it's important to ensure effective technique in all eight stages. The following are the most important Winning Pretty technical elements to consider in each of the stages:

Start (Stage 1)

The start of the serve is important because players need to have the right grip and a good stable base to begin the motion. Mark Kovacs has cautioned that many aspects of the start are stylistic rather than a fundamental commonality, and he warns players not to prioritize style over fundamentals (1). The grip should be a continental or close to continental. For a power serve, a grip too far towards the top bevel of the racquet (bevel 1), can reduce power.

The stance should be sideways with the front foot near parallel to the baseline. Some coaches recommend pointing the foot at the net post, but many modern pros align their feet near parallel to the baseline.

Release (Stage 2)

It's important to toss with a straight arm with minimal elbow or wrist flexion. I like to remind my students to toss with the shoulder joint while lifting the ball to avoid any tendency to flick the toss upwards with the wrist or elbow joint. The ball should be held in the fingertips and released like a flower blossoming or star shape. Typically, the tossing arm should be lowered toward the front leg and can be situated between 12 (perpendicular to the baseline) and 3 o'clock (parallel to the baseline) in relation to the server's trunk.

The arm positions and rhythm are crucial to a successful toss and can affect the kinetic chain later during the next stages of the service action. The ball should be released from the tossing hand between the eyes and top of head level (1). In the Winning Pretty method, there are several acceptable ways the arms can start and then move up and down:

Classic arms down-and-up together along with the Abbreviated take-up (which is more rare).

Tossing arm leading; racquet arm lagging. The cobra variation, with the racquet pointed down initially, is also popular on tour.

Loading (Stage 3)

The L-shape or power position in the dominant arm is essential to producing a powerful serve. The tossing arm continues upward and points to the ball overhead. The knees bend and load the energy in the legs. The hips and trunk should coil creating a separation angle between the upper body trunk and hips.

There are two types of stances used to load the legs during the loading stage: platform and step-up (pinpoint). Research shows that the step-up technique creates more vertical energy allowing athletes to jump higher while the speed of the serve is the same for both stances (2). The back leg bends and extends more than the front leg on the step-up style, contributing to higher vertical ground reaction forces, according to researchers (4,5). "The back leg provides most of the upward and forward push, whereas the front leg provides a stable post to allow rotational momentum," according to Kovacs and Ellenbecker (1).

Cocking (Stage 4)

The cocking stage describes the moment where the shoulder reaches its point of maximal external rotation in the racquet drop behind the back. The most important aspect of the cocking stage is sequencing the leg drive with the racquet drop and acceleration. The legs should initiate the racquet drop and acceleration rather than the other way around. Dr. Brian Gordon has shown through high-speed video study that, in high level servers, the leg drive upwards starts before the racquet drops down behind the back. Gordon has also demonstrated that most junior and recreational players do the opposite: They drop the racquet before firing the legs upward. Girard and colleagues have demonstrated that advanced servers initiate the leg drive sooner than lower level servers (6). The result of a late leg drive is a loss of power because the stretch-shortening cycle is not optimized to enhance elastic energy return from the tendons in the shoulder and arm complex (8).

The cocking phase requires a good range of motion (ROM) in the shoulder and spine. Mark Kovacs says that the best servers in the world demonstrate tremendous thoracic mobility. According to Kovacs, "The lower spine should be stable and the upper thoracic spine needs to be flexible. That's the key. So there is a back arch on the pro serve, but not in the lower back " (citation). Bruce Elliott has shown that more range of motion during the racquet drop generates more racquet head speed (7). Poor cocking indicates a need for stretching and mobility training, which can dramatically improve power production. The Kovacs Institute offers many research based programs available online to help improve strength and ROM to improve the serve, and I recommend them

Acceleration (Stage 5)

In this stage, the racquet accelerates up to the impact in less than 1/100 of a second for professional players, according to research (1). This stage should literally occur in the blink of an eye when performed correctly. It is important to accelerate upwards with the racquet and wrist on edge, pronating the forearm just before impact. Many players incorrectly accelerate upwards with an open palm, which indicates early pronation. Some players open their shoulders too early during this stage, which is another common problem. Says Kovacs, "The speed of back hip drive has the strongest correlation to maximum power delivery."

Contact (Stage 6)

It''s critical to fully extend the body during contact to hit the serve from the highest point possible. Players need to work on optimizing their lower body movement focusing on triple extension (ankle, knee, and hip), the upright posture of the trunk, and stretching of their arm fully to meet the ball at the highest point possible at impact.

Deceleration (Stage 7)

During deceleration the forearm continues to pronate and the shoulder continues to internally rotate, which has been called "long-axis pronation" in the biomechanical literature, a term coined by Dr. Bruce Elliott. A straight-arm finish without long-axis pronation indicates an acceleration or mechanical problem earlier in the kinetic chain.

Finish (Stage 8)

The finish is the conclusion of the serve and should be balanced with good body control. The player should land on the front leg with the scorpion pose. The player should jump over the baseline into the court, indicating a strong weight transfer forward. The head should be level with the eyes fixated on the target and opponent. The trunk should maintain good posture and not collapse. The server should explode up and into the court without fading left or right.